This invention relates to air control dampers and more particularly to an air control damper in a zoned air conditioning system.
The inventive damper assembly is particularly well suited for the residential heating, ventilating and air conditioning ("HVAC") market. It is particularly well suited for the home retrofit market although it could also be applied in new construction or in smaller commercial applications.
Generally, residential HVAC systems heat or cool the air which is discharged at constant pressure and at constant air quality by the blower and distributed to the respective rooms through the respective branched ducts, so that each room is cooled or warmed. Therefore, when the quantity of air for a particular room is to be reduced by a damper in order to lower the temperature of the room when the system is in the heating configuration, the quantity of air which is distributed to other rooms increases so that the temperature in the other rooms also changes.
There have been various systems which provide for the zoned control of HVAC systems for home applications. One example is in U.S. Pat. No. 4,243,174 which provides for the automatic opening and closing of electrically operated dampers to control the air flow into a series of rooms. The motor operated damper utilizes a solenoid to rotate the damper assembly. However, this motor operated damper assembly utilizes a linkage and spring assembly to open and the close the damper when the solenoid is operated. The disadvantage of this damper assembly is that it does not securely lock the damper in the opened or closed position and may inadvertently rotate from the desired position due to the flow of air or lack thereof. Furthermore, the mechanism is not adapted to be mounted on ducts of varying size or configuration. It appears that the solenoid is directly fasten to the air duct which on larger diameter air ducts would be acceptable, but on the small diameter air duct the solenoid would not be able to be securely fastened to the duct without a suitable adaptor.
Another example of a zoned HVAC system which utilizes air control mechanisms in the ducts is illustrated in U.S. Pat. No. 4,600,144. In this patent there is illustrated a bladder-type flow control device which, when inflated, blocks off air flow through the duct. Other forms of duct control mechanisms are illustrated in this patent, one of which utilizes a standard mechanical damper which limits the air flow through the duct. However, none of these dampers assemblies employ a motor control mechanism which securely locks the damper in place in the opened or closed position.